3,775 research outputs found
Locally convex quasi C*-algebras and noncommutative integration
In this paper we continue the analysis undertaken in a series of previous
papers on structures arising as completions of C*-algebras under topologies
coarser that their norm and we focus our attention on the so-called {\em
locally convex quasi C*-algebras}. We show, in particular, that any strongly
*-semisimple locally convex quasi C*-algebra (\X,\Ao), can be represented in
a class of noncommutative local -spaces.Comment: 12 page
An invariant analytic orthonormalization procedure with an application to coherent states
We discuss a general strategy which produces an orthonormal set of vectors,
stable under the action of a given set of unitary operators ,
, starting from a fixed normalized vector in \Hil and from a set
of unitary operators. We discuss several examples of this procedure and, in
particular, we show how a set of {\em coherent-like} vectors can be produced
and in which condition over the lattice spacing this can be done
Some invariant biorthogonal sets with an application to coherent states
We show how to construct, out of a certain basis invariant under the action
of one or more unitary operators, a second biorthogonal set with similar
properties. In particular, we discuss conditions for this new set to be also a
basis of the Hilbert space, and we apply the procedure to coherent states. We
conclude the paper considering a simple application of our construction to
pseudo-hermitian quantum mechanics.Comment: in press in Journal of Mathematical Analysis and Applications. arXiv
admin note: text overlap with arXiv:0904.088
Balloon-borne package temperature controller
Simple, inexpensive, lightweight enclosure traps upward long wave radiation of earth while reflecting harsh solar radiation in upper atmosphere. It warms enclosed instruments in cold regions and protects them from overheating during the day. Device can be attached to balloon system without any changes in experimental design
Apparatus for controlling the temperature of balloon-borne equipment
A novel apparatus for controlling the temperature of balloon-borne equipment is disclosed, the apparatus serving to utilize the radiant energy emitted by the earth and its atmosphere so as to control the temperature of equipment. The apparatus comprises a housing to be carried aloft by a balloon and defining an enclosure for an instrumentation package. The enclosure includes an upper shield portion as well as a bottom window portion at the base, the bottom window facing the earth below during flight. The upper shield portion is constructed of a material such as aluminized Mylar, which serves to reflect direct sunlight
Returned Solar Max hardware degradation study results
The Solar Maximum Repair Mission returned with the replaced hardware that had been in low Earth orbit for over four years. The materials of this returned hardware gave the aerospace community an opportunity to study the realtime effects of atomic oxygen, solar radiation, impact particles, charged particle radiation, and molecular contamination. The results of these studies are summarized
OSS-1/contamination monitor
A 20-cm high, 18-cm wide, and 30-cm long (8x7x12 inch) box weighing about 7 kg (15 lbs) and consuming about 7 watts of power was carried on the OSS-1 pallet to monitor the mass build-up or accretion of condensible, volatile materials on surfaces in the shuttle bay during all phases of ascent, on-orbit, and descent. Passively thermally controlled, the box holds two witness samples and four actively temperature controlled quartz crystal microbalances (TQCM) whose temperature can vary from -60 C to +80 C. Graphs show the accretion indicated by the TQCM during the launch and early orbital phase. Conditions during tail to the Sun, nose to the Sun, and bay to the Sun attitudes of the shuttle during STS-3 are reflected in temperatures indicated by the OSS-1 thermistor. These temperatures influence outgassing rates of various materials as well as measurements made by the contamination monitor package. The parameters that bear on TQCM measurements data are shown in graphs and discussed
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